Explosions, with occasional jolts of lightning can be seen in Farnsworth's lab. The professor, in agony, screams for help, but Bender continues sleeping, and Fry continues attempting to take Leela out on a date. She rejects him, saying she left her toaster on. They speak loudly to be heard over the booms and zaps from upstairs, where the Professor, still in distress, cries out to Buddha, then Zeus, then God, for assistance. Fry asks her real reasons for not wanting to go out, over the invocations from the lab. Farnsworth demands Satan's help, noting, "You owe me!" Still loudly, Leela replies, "..I have sweaty boot rash!" Unfortunately, the explosions end just before she says it. Amy ends up overhearing, and notes it's why she's sitting far away from her. Fry laughs...and asks again for a date.
In the conference room, filled with debris due to the explosion, Farnsworth happily states with his usual "good news" that's he's technically still alive, but he needs them to drop off the Parallel Universe Box containing the experiment that nearly killed him into the sun. Only hurling it into the "thermonuclear inferno" of sun itself, he explains, will "ensure it's total destruction".
A curious Zoidberg tries to look in the box, Farnsworth convinces him, with a hammer, to desist; the Planet Express crew are warned that whatever is inside is probably beyond their comprehension. Even Hermes becomes inquisitive; Farnsworth again uses the hammer. Dramatically stating that no matter what they're all forbidden from looking inside the box, he then notes how tantalizing it is.
Zoidberg, food crazed, tries frantically to open the box. A gun wielding Hermes scares him, Bender, and Fry away from the box. Hermes then gives the gun to Leela and tells her to shoot the three. Leela adds, "Right. If they try to look in the box." Hermes shrugs. "Whatever".
Fry, and Bender are now in the conference room, and Fry decides to forget about the box. Bender calls Fry naive and states Farnsworth was joking. Fry isn’t fooled, so Bender drops the charade, and simply tells Fry to follow him. They go to the basement and crawl into a superheated steam vent, using it to get directly above the box. Bender replaces his regular eyes with periscopes, to scout the room, and notices Leela is sleeping. Laughing, he extends his arm, and takes the mystery box with ease.
Back in the basement the two open the box and discover the box contains... tangled Xmas lights, and unlabeled booze in a wide mouth bottle. Leela, who was only pretending to be sleeping, states the decoy box should distract the two, and gets up. It turns out she was sitting on the real box all along. Satisfied that protecting the box will be a simple chore since no one's curious about it, she tries to read a magazine, unfortunately, she is now also starting to show curiosity about the box.
Nevertheless, Leela has managed to keep the box safe throughout the night, and the clock in the room strikes 7 am. Mildly irritated by now, she complains that protecting the box made her miss an evening of television watching, and decides to drink some coffee. She walks up to the coffee dispenser, and starts to put in change, but pulls back, deciding to flip the coin to determine whether or not she should look in the box. Heads she looks, and tails she doesn’t.
The coin turns up heads, and an elated Leela walks up to the box, but her sense of duty kicks in and she turns around. Still, since she promised the coin, she opens the box, and looks in. She curiously notes the box is much deeper than it should be, accidentally falls into it, and comes out of a different colored box, bumping her head in the process. A hurt Leela proclaims her lawyer will hear about this, and Fry’s voice is heard asking what she did. She panics and asks “what do you mean why was I looking in the box?”. A Fry with black hair, and a green jacket, asks her why her hair is different.
A gold colored Bender walks in and Leela squints and asks if he is Bender. With his usual arrogance, he states yes. Next, Professor Farnsworth walks into the room, but he has an odd scar going around his head. Then, another Leela comes in - with red hair. This shocks everyone and Farnsworth realizes that he created an alternate universe, which he presumes to be evil. He has his "good" Leela go into the other universe to bring others to them. Leela brings back everyone else except Hermes. The two Professors then argue over who created what universe and decided to have their counterparts watch each other. They then declare the universe there are in is Universe 1 and the other Universe A.
As the crew talk to their counterparts, it is revealed that Fry-1 and Leela-1 are married, due to a flip of the coin and that Fry-1 bought Leela-1 a diamond scrunchy and they were married; Fry-A was beaten up at a Neil Diamond concert by a man named Scrunchy; Farnsworth-1 had cut out his own brain through flip of a coin and managed to get it back in. Eventually, after checking the scriptures, the Professors decide that neither universe is evil. However, just as Hermes-1 comes in, the Professors realize that Hermes-A will be going to the sun to destroy the box. But when they try to get the box out of the aquatic tank, they find it gone, stolen by the two Zoidbergs, who had been feeling unappreciated. They attempt to recreate the box to their universe only to create several others. When the Zoidbergs arrive back with the box, they escape into other universes. Therefore, everyone else had to search every other universe, grabbing wire to find their way back. After tireless searching, they find the Zoidbergs in Universe 420 and managed to get back to Universe-A to stop Hermes from destroying their box.
Back at Planet Express, both Universe-1 and A pull their respective boxes from the inside-out. Essentially, Universe-A has a box containing their own universe. Bender shakes the box a little, causing an earthquake. As Fry sits on the box to watch television, the universe momentarily folds in on itself.